Statins rise cytoplasmic calcium level [Ca2+]i in cultured endothelial cells

Recently, we have shown that some HMG-CoA reductase inhibitors (statins) induce immediate pleiotropic effects in vascular endothelium both in vivo and in vitro, to mention only PGI2-mediated thrombolysis in rats and NO-mediated endothelium-dependent vasodilation in guinea pig coronary circulation. Here we look whether immediate endothelial effect of statins is associated with mobilization of intracellular calcium ions [Ca2+]i in cultured bovine aortic endothelial cells (BAEC). We analyzed the effects of various statins (atorvastatin, cerivastatin, simvastatin, lovastatin and pravastatin at concentration of 10-30 microM) on [Ca2+]i in BAEC in comparison to responses induced by bradykinin (Bk) (10 nM), adenosine diphosphate (1 microM), acetylcholine (100 nM), adrenaline (10 microM), serotonin (10 microM) or calcium ionophore A 23187 (0.1 microM) using FURA-2 according to fluorimetric method of Grynkiewicz et al. Basal [Ca2+]i level in BAEC was between 60 and 100 nM. Bk was the most potent to induce [Ca2+]i response. Delta[Ca2+]i induced by Bk was 331.9 +/- 19.49 nM (n = 36). Delta[Ca2+]i induced by statins (30 microM), i.e. atorvastatin, cerivastatin, simvastatin, lovastatin and pravastatin were 66.4 +/- 7.38% (n = 6), 54.8 +/- 10.12% (n = 5), 58.8 +/- 13.9% (n = 8), 27.7 +/- 7.19% (n = 5) and 0% (n = 5) of the response induced by Bk (10 nM), respectively. In summary, all statins tested, except pravastatin, induce immediate increase in [Ca2+]i in endothelium. This pleiotropic activity of statins in endothelium, most likely not related to the inhibition of HMG-CoA reductase, may represent an intracellular correlate for the immediate release of NO and PGI2 by these drugs that was reported by us previously.